The internal energy U of gasses is a function of T and V U

. The internal energy, U, of gasses is a function of T and V. U is a state function. Which of the following equations could be the total differential for U for non-ideal gas? Note A and B are constants and R is the gas constant. Explain why in 2-3 sentences. 2AT R(V-B) a. dU= (V-B)2 (V-B)2

Solution

dU = (Cp)dT - PdV

It is important to know that internal energy U decreases with increase in volume at constant T. Answer is option b. because -2AT/(V-B)² is negative unlike option a.